1. Field of the Invention
The present invention relates to a differential device applied to conveyance means such as automobiles.
2. Description of the Related Art
As is known, a driveline of an automobile requires one or more differential assemblies for differentially distributing torque generated by an engine to a plurality of shafts and axles, each of which facilitates relative rotation between a pair of output shafts. One type of differentials is known as a parallel axis helical gear differential, which is provided with a planetary gear set typically having helical output gears and paired sets of helical pinion gears.
Japanese Patent Application Laid-open No. H07-77263 (in particular, FIG. 3) discloses an art of a parallel axis helical gear differential, in which a central piece receives torque from an engine and the received torque is distributed to left and right follower gears via a differential case and paired sets of pinion gears. In each pair of the pinions, one pinion meshes with the left follower gear and another pinion meshes with the right follower gear. For mutual meshing of the pinion gears, both the pinions are extended toward a center in the axial direction of the differential case and have overlaps around the central piece.